Determination of cholesterol oxidation products in the supercritical carbon dioxide extract of egg yolk powder: Comparison with conventional liquid solvent extraction methods

摘要

Neat SC-CO2 extraction was compared with the conventional Folch and the Bligh and Dyer (B&D) extraction, as a sample preparation technique for the determination of cholesterol oxidation products (COPS) in spray-dried egg yolk. Total lipids could be extracted in analytical scale (2 g sample) using four dynamic extraction steps of 30 min each, at 40 degreesC and 51,700 kPa. The recovery of total COPs in the SC-CO2 extract (35 mug COPs g(-1) extract) was not statistically different with respect to the Folch and B&D extract. SC-CO2 extraction showed important advantages, such as the elimination of chlorinated solvents and the reduction of sample manipulation and preparation time. The formation of artifacts of COPS due to the acidic properties of CO2 during the sample preparation did not reach a significant extent.